Impact of Vitamin C on Pain Detection and Tolerance Threshold

NCT ID: NCT06971315

Last Updated: 2025-05-14

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: EARLY_PHASE1
• Total Enrollment: 38 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-06-02
• Study Completion Date: 2025-12-31

Brief Summary

Non-opioid treatments are increasingly sought after for managing acute pain. Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) (e.g., Advil, Motrin, Naproxen) combined with acetaminophen (e.g., Tylenol) have become an alternative for relieving acute pain. However, many patients cannot tolerate or have contraindications to NSAIDs and acetaminophen.

There is therefore an urgent need for studies evaluating the analgesic effects of vitamin C in the context of acute pain. Our study is conducted with healthy volunteer participants receiving either vitamin C or a placebo to assess the analgesic effect of vitamin C by comparing pain detection and tolerance thresholds.

Detailed Description

Opioid-free treatments are increasingly sought for acute pain and NSAIDs have become an alternative to treat acute MSK pain and are often administered in addition to acetaminophen. However, NSAIDs can produce important adverse events and are contraindicated in many patients with comorbidities (e.g., heart disease, renal failure). Similarly, acetaminophen is contraindicated in patients with active liver disease or severe hepatic impairment.

Vitamin C has shown opioid sparing and anti-inflammatory effects mostly in postoperative contexts. Vitamin C has also demonstrated very low toxicity and rare contraindications at the dosage used in this study. Demonstrating that vitamin C increases pain detection and tolerance thresholds, thereby exhibiting an analgesic effect, could offer a valuable alternative or adjunct for patients who cannot tolerate or have contraindications to NSAIDs or acetaminophen, helping to reduce opioid use. With an aging population, the number of affected patients is expected to rise significantly.

The primary outcome is the pressure pain detection threshold (PPDT) measured with an algometer one to three hours after the last dose of the study drug (24 hours after the first dose of vitamin C or placebo).

Secondary outcomes are PPDT one to three hours after the first study drug dose, PPTT one to three hours after the initial dose and last dose of the study drug, and adverse events from the algometer or the vitamin C.

Conditions

Pain, Acute

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: TRIPLE

Study Groups

Vitamin C

Three doses of 900 mg of vitamin C taken orally every 12 hours for 24 hours (baseline, 12 hours and 24 hours)

Group Type: EXPERIMENTAL

Vitamin C

Intervention Type: DIETARY_SUPPLEMENT

Three doses of 900 mg vitamin C taken orally (baseline, 12 hours and 24 hours)

Placebo

Three doses of 900 mg of placebo taken orally every 12 hours for 24 hours (baseline, 12 hours and 24 hours)

Group Type: PLACEBO_COMPARATOR

Placebo

Intervention Type: OTHER

Three doses of 900 mg placebo taken orally (baseline, 12 hours and 24 hours)

Interventions

Vitamin C

Three doses of 900 mg vitamin C taken orally (baseline, 12 hours and 24 hours)

Intervention Type: DIETARY_SUPPLEMENT

Placebo

Three doses of 900 mg placebo taken orally (baseline, 12 hours and 24 hours)

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

1. Age ≥ 18 to 65 years old;

2. No acute or chronic pain;

3. No pain medication;

4. French or English-speaking

Exclusion Criteria

1. Currently using vitamin C supplements;

2. Pain in the last week or active cancer;

3. Unavailable for follow-up;

4. Allergy to milk (lactose in the placebo), or vitamin C,

5. Treated with cyclosporine or warfarin (interaction with vitamin C);

6. Pre-existing oxalate nephropathy, liver cirrhosis or hemochromatosis;

7. Evidence of joint or overlying skin infection in the areas of testing.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de Montreal

OTHER

Sponsor Role: lead

Responsible Party

Raoul Daoust

Dr Emergency Medicine, Professor, Clinician Researcher

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Hopital du Sacre-Coeur de Montreal

Montreal, Quebec, Canada

Countries

Canada

Central Contacts

Martin Marquis, MSc

Role: CONTACT

martin.marquis.cnmtl@ssss.gouv.qc.ca

514-338-2222

Other Identifiers

2025-2991

Identifier Type: -

Identifier Source: org_study_id